Method for cervical videoscopy

ABSTRACT

A simple yet highly useful cervical videoscope has been provided which can easily be used by the doctor to examine the cervix for cancerous lesions or other abnormalities. Also, because of the small size of the camera there is sufficient space between the camera and the blades of the speculum for inserting forceps and other instruments that may need to be used. By using the cervical videoscope in combination with a monochromator the physician can step the wavelength of light from one end of the light spectrum to the other until he observes florescence which identifies abnormal cells. Thereupon, he can destroy the cells by use of a laser beam. When he observes that no more florescence is occurring, then he can discontinue the operation of the laser, knowing that the lesion has been completely eradicated. Also, a channel for drawing a suction to remove smoke created by the destruction of the lesion can be provided. Finally, the camera is adjustable along a guide on the fixed blade of the speculum to focus it.

This is a division, of the application Ser. No. 291,238 filed 12/28/88,now U.S. Pat. No. 4,905,670.

TECHNICAL FIELD

This invention relates to a cervical videoscope and particularly to onewhich allows inspection of the cervix under specific selected wavelengthof light and provides for subsequent treatment of any lesions found onthe cervix.

BACKGROUND ART

Examination of the cervix for cancer and viral infections are done nowwith a device called a colposcope. This device is a binocular microscopewhich is placed near the patient It supplies a bright light, (whitelight and green light) and the operator looks through the eyepieces ofthe colposcope much like looking through field glasses. This is donewith a vaginal speculum in place. Some of the devices have cameraattachments for still picture photography. The physician looks at thetissue looking for whitened areas after treatment with 3-5% acetic acid.The acetic acid whitens tissue which is low in mucous, such as cancercells. The physician also looks for clusters of blood vessels which mayindicate new growth such as cancer. The effectiveness of this colposcopyprocedure is only 85%, and this is with a very experienced physiciandoing the procedure. Also, the colposcope is difficult to use because ofits size and weight.

Over the years various vaginal speculae have been developed. Among theseare the following:

Casaneda U.S. Pat. No. 4,210,133 discloses a vaginal speculum having amicroscope mounted thereon which has a light source for illumination andis longitudinally adjustable for focusing.

VanDerBel U.S. Pat. No. 4,597,383 discloses a vaginal speculum havingoptical fiber illumination means attached thereto.

Burgin U.S. Pat. No. 4,638,792 has an adjustable speculum with anincorporated light system.

Walsh U.S. Pat. No. 4,619,248 discloses a light attachment for aspeculum.

Wider et al. U.S. Pat. No. 4,562,832 illustrates in FIG. 6 a fiberopticlight pipe installed in the lower jaw of the vaginal speculum.

Burgin U.S. Pat. No. 4,502,468 has an adjustable speculum with anincorporated lighting system.

Whitman U.S. Pat. No. 3,789,835 discloses an illuminating attachment forvaginal speculum.

Stafl U.S. Pat. No. 4,300,570 has a diagnostic method of projecting theimage of a cervix photograph onto a screen. However, the camera is notmounted to the speculum.

Hasson U.S. Pat. No. 3,789,829 discloses a radium applicator mounted toa vaginal speculum.

Walden et al. U.S. Pat. No. 3,037,505 discloses a speculum with a spraytube carried by a jaw of the speculum.

Tanikawa et al. U.S. Pat. No. 4,461,558 discloses an endoscopicphotographing apparatus applicable to all types of endoscopes and usestherefor.

Toyota et al. U.S. Pat. No. 4,697,210 discloses an endoscope forobserving the interior of a cavity in a human body with the imagedisplayed on a TV screen.

The last two patents are representative of many observation techniquesavailable for use with endoscopes.

None of these devices have served to increase the detection rate ofcancer and the early treatment thereof.

DISCLOSURE OF THE INVENTION

A cervical videoscope apparatus is provided which includes a vaginalspeculum having a first fixed blade, a second blade mounted for pivotalmovement toward and away from the fixed blade and spring means normallyurging the second blade toward the fixed blade. The improvement includesa video camera mounted on one of the blades for viewing the cervix,means providing light to the cervix, means for focusing the camera on aselected site on the cervix and means for providing a signal from thecamera to a video screen for viewing the cervix and identifying lesionsthereon. The focusing means may include a track mounted longitudinallyalong one of the blades and means for adjusting the camera along thetrack for focusing The light providing means can include a light carrieron the track for providing light to the cervix. In addition, means isprovided for selecting light for illumination of the cervix at any oneof a range of light frequencies. This can be broad frequency light,monochromatic light or laser light for illumination. A particularlyuseful light frequency has been found to be from 200 nm through 1100 nm.A suitable means for stepping sequentially through the frequencies is amonochromator. The monochromator converts light from a light source to asingle frequency at an output in the form of a rectangular slit. A lightcarrier is provided which includes a bundle of optical fibers having afirst end in a form of a rectangular collar for receiving the outputfrom the monochromator and a circular collar at the other end fordirecting a round column of light onto the cervix.

A laser carrier can be provided on the track for directing a laser beamor laser fiber to vaporize lesions on the cervix. Also, a suction tubecan be provided on the track to remove smoke created when the lesionsare vaporized with the laser.

The invention also provides a method for locating and surgicallyremoving lesions This method comprises the steps of selectivelyilluminating the cervix with a light of different frequencies, observingthe cervix as it is illuminated with each light frequency, locatinglesions by their florescence or reflectance under one of the selectedlight frequencies and removing the lesions which have been located. Thelesions may be removed by using a laser to vaporize them and theactivation of the laser can be terminated in response to termination ofany florescence at the lesion site.

Additional advantages of this invention will become apparent from thedescription which follows, taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of a cervical videoscope constructed inaccordance with this invention and positioned for use;

FIG. 2 is an enlarged rear elevation of the cervical videoscope of FIG.1;

FIG. 3 is a longitudinal section, taken along line 3--3 of FIG. 2;showing further details of the video camera and associated laser tubeand suction tube;

FIG. 4 is a longitudinal section, taken along line 4--4 of FIG. 2,showing details of the track mounting for the video camera;

FIG. 5 is an enlarged cross-section, taken along line 5--5 of FIG. 4,showing further details of the video camera and track mechanism;

FIG. 6A is a diagrammatical view of video camera used in conjunctionwith a monochromator;

FIG. 6B shows details of the optical bundle connector of FIG. 6A forconverting a rectangular light slit into a circular beam;

FIG. 7 is a diagrammatical view showing the video camera used with aband pass filter to provide monochromatic light; and

FIG. 8 is a diagrammatical view showing the camera used directly with alight source.

BEST MODE FOR CARRYING OUT THE INVENTION

In accordance with this invention a cervical videoscope V is attached toa speculum S, as shown in FIG. 1. In use, the speculum is inserted intothe vagina as shown. The speculum includes a lower fixed blade 10 havinga depending handle portion 12. An upper pivotal blade 14 generallyextends parallel to lower blade 10 and has depending ears 16 at theproximate by which it is pivotally mounted on a support 18. Support 18has a yoke 20 at the upper end thereof to which ears 16 are pivoted. Thelower portion of support 18 has a longitudinal slot 22 through which athumb screw 24 extends for tightening against handle 12 to adjust thespacing of upper blade 14 from lower blade 10.

At the pivotal connection between ears 16 and yoke 20 a spring (notshown) may be provided which tends to pivot the upper blade 14 in acounterclockwise direction, as viewed in FIG. 1, so that it is movedtoward fixed blade 10. However, this movement is limited by the positionof nut 26 on threaded adjustment rod 28. Conveniently, rod 28 extendsthrough a lever 30 which is fixedly attached to one of the ears 16 ofupper pivotal blade 14. Thus, when nut 26 is moved outwardly along rod28, blade 14 will pivot toward blade 10 and when nut 26 is movedinwardly along rod 28 blade 14 will pivot away from blade 10.

The videoscope V includes a camera 32 mounted on lower blade 10. Alongitudinal guide member 34 is fixedly attached to stationary blade 10,as best seen in FIG. 4. Worm gear 36 is mounted within guide 34, asshown, for rotation about a pin 38. Camera 32 is provided with a rack 40extending longitudinally therealong and attached thereto. The teeth ofthe rack engage worm gear 36. A control shaft 42 is attached to pin 38and has a knob 44 for rotating worm gear 36 and thereby adjusting camera32 longitudinally along guide 34. This provides a means for focusing thecamera on the particular area of the cervix which is being investigated.Advantageously, the camera is sealed against moisture leakage into theelectronics to allow soaking in a sterilizing solution between usage ondifferent patients. It is usually backfilled with nitrogen duringmanufacture after air and moisture is removed in a vacuum chamber. A CCDsensor can be used to pickup the image and transmit a signal to thevideo monitor for processing. The camera case can be made of titanium orother metal which is substantially non-corrosive or it can be made ofplastic. The camera can also be sterilized with a gas, such as ethyleneoxide.

At the forward end of camera 32 is an optical lens system 46 forreceiving an image from the cervix. This lens system may have zoomcapabilities to provide 2X to 200X magnification. The image is projectedby the camera along cable 48 to a video control unit 50 for projectingan image onto monitor 51 shown in FIG. 6A. As shown in FIG. 6A, a lightsource, such as xeon light source, 52 projects light through amonochromator 54. Other light sources, such as halogen, mercury vapor,mercury arc, incandescent or laser can be used. The monochromator hasthe ability to project light of a single wavelength from the lightsource 52 and to do so in stepped increments. It should have a highoutput with a frequency range from 200 nm to 1100 nm. By this means, aphysician can look at the video monitor while stepping through eachlight frequency and look for fluorescing lesions on the cervix. It hasbeen found that different types of lesions will fluoresce in response todifferent light wavelengths.

The light exits the monochromator 54 through a slit 56 shown in FIG. 6Band enters one end of a bundle of optical fibers 58. Conveniently, oneend of optical fiber bundle 58 is mounted within a rectangular collar 60which mates with the end of monochromator 54 for receiving light fromslit 56. The other end of optical fiber bundle 58 has a circular collar62. Collar 62 and the cable 48 for video control unit 50 connect to acable or light carrier 64 wherein the individual optical fibers 64 arepositioned around the outside of the lens system 46, as best seen inFIG. 5. Thus, the light image of selected wavelength can be directedsubstantially uniformly onto the surface of the cervix. As themonochromator steps the light from one end of the light spectrum to theother, a wavelength will be encountered in which cancerous lesions orlesions caused by viral infection will fluoresce and therefore will beidentifiable on the video monitor.

When this occurs, these lesions can be destroyed by use of a laser beam.This is accomplished by directing the laser beam along an optical fiber66 which extends through a channel 68 attached to guide member 34.Optical fiber 66 can be provided with steering cables (not shown) fordirecting the laser to the lesion cite. A KPT-532 laser, carbon dioxidelaser or a YAG laser having been found to be satisfactory. Conveniently,a suction channel 70 can be provided adjacent to laser channel 68 forremoving smoke caused by destruction of the lesions. This channel may beconnected to a vacuum hose 72, as shown in FIG. 3.

An alternative arrangement is shown in FIG. 7 wherein a removable bandpass filter 74 is provided between the light source 52 and optical fiberbundle 58 for providing selected wavelengths of light to the cervix. Aband pass filter is useful when the patient is treated with a substancewhich will accumulate at the lesion cite and be fluorescent under aknown wavelength of light. In such a case the band pass filter can beselected to transmit only the desired wavelength frequency. Suitablesubstances are hematoporphyrin (HPD) or a derivative thereof, such asdehematoporphyrin either (DHE), corins, pheophorbides and coumerins.Also Rhodamine-123 can be sprayed or painted on the cervix. Finally, thecite can be tagged with a monoclonal antibody.

In a still further simplified embodiment, shown in FIG. 8, the lightsource 52 is directly connected to optical fiber bundle 58. Thisembodiment can be used wherein the material at the lesion cite on thecervix will have florescence over a wide range of light wavelengths foridentification of lesions.

A number of add-ons may be provided to the apparatus just described.Among these are a character generator for the patient's name, age, etc.,video recorder, video printer and suitable image processors.

From the foregoing, the advantages of this invention are readilyapparent. A simple yet highly useful cervical videoscope has beenprovided which can easily be used by the doctor to exam the cervix forcancerous lesions or other abnormalities. Also, because of the smallsize of the camera there is sufficient space between the camera and theblades of the speculum for inserting forceps and other instruments thatmay need to be used. By using the cervical videoscope in combinationwith a monochromator the physician can step the wavelength of light fromone end of the light spectrum to the other until he observes florescencewhich identifies abnormal cells. Thereupon, he can destroy the cells byuse of a laser beam. When he observes that no more florescence isoccurring, then he can discontinue the operation of the laser, knowingthat the lesion has been completely eradicated. Also, a channel fordrawing a suction to remove smoke created by the destruction of thelesion can be provided. Finally, the camera is adjustable along a guideon the fixed blade of the speculum to focus it.

It should also be noted that the device may be detached from the vaginalspeculum and used along with the sophisticated light sources to look forsimilar lesions in the rectal area or on other body surfaces.

This invention has been described in detail with reference to particularembodiments thereof, but it will be understood that various othermodifications can be effected within the spirit and scope of thisinvention.

I claim:
 1. A method of locating and removing cervical lesions, said method comprising the steps of:providing a light source to supply light over a wide spectrum of frequencies; successively stepping through each frequency to sequentially illuminate the cervix with light of each successive frequency; observing the cervix as it is illuminated with each successive light frequency; locating lesions by their florescence or reflectance to one of the selected light frequencies; and removing the lesions which have been located.
 2. A method, as claimed in claim 1 including the further step of:using a laser to vaporize the lesions to remove them.
 3. A method, as claimed in claim 2, including the further step of:terminating the use of the laser on each lesion in response to the termination of any florescence at the lesion site.
 4. A method, as claimed in claim 1, including the further step of:identifying the type of lesion by the wavelength at which it becomes florescent. 